Technical Nte Structural Cncrete Sftware System TN230_PT_design_prcedure_FP_12 053007 DESIGN STEPS USING ADAPT FLOOR-PRO 1 Bijan O Aalami 2 This Technical Nte utlines the steps that yu have t fllw in designing a pst-tensined flr system, using the ADAPT- FLOOR Pr. FLOOR-Pr is a finite-element based prgram specifically develped and tailred fr the design f pst-tensined flr systems. It is assumed that yu are familiar with the basics f the prgram and, as a minimum, have gne thrugh its tutrials and wrkshp examples. N attempt is made t prvide extensive details f the steps listed. Where needed, yu are advised t cnsult ther literature by ADAPT. The prpsed sequence f steps is summarized in the fllwing flw chart. There are ther alternatives t the prpsed sequence. Hwever, it is believed that the flw chart given reduces the likelihd f errrs, and leads t early detectin and crrectin f mistakes, if they ccur. The numbers given in the circles indicate the availability f ther literature frm ADAPT that cver in greater detail the marked tpic. If yu have an electrnic file f the flr slab and als have sme knwledge f AutCad. Create the layers in AutCad that are ging t be used by FLOOR-Pr 3. Create a Framing Plan referred t as cncrete utline. 4 Open FLOOR-Pr Imprt and Calibrate the flr plan Create and Validate the Structural Mdel If the dwg was preprcessed int prper layers either by yu r a drafting technician in yur ffice, pen the layers f each f the structural cmpnents ne after the ther and transfrm them t structural cmpnents. If the dwg was nt pre-prcessed, simplify and rganize the imprted infrmatin. Yu will create tw grups f layers ne t generate the structural mdel and the ther t help yu generate the structural dcuments. Create layers fr drafting the structural drawings (rebar and PT drawings) 5. These layers will be used later t draft the cncrete utline (framing plan). Create layers that yu will be using t cnvert the drawing int structural mdel fr analysis and design 6 1 Cpyright ADAPT Crpratin 2006 2 Prfessr Emeritus, San Francisc State University 3 Refer t the Wrkshp manual, r the assciated Technical Nte n the creatin f layers used in FLOOR-Pr 4 Cntents f the Framing Plan, als referred t as Cncrete Outline. See appendix f this Technical Nte. 5 Refer t the wrkshp bklet fr the prcedure 6 Refer t the wrkshp bklet fr the prcedure E-Mail supprt@adaptsft.cm 1733 Wdside Rad, Suite 220, Redwd City, Califrnia, 94061, USA, Tel: (650) 306-2400 Fax (650) 306 2401
FLOW CHART OF DESIGN PROCEDURE IN BUILDER Technical Nte Design_prcedure_builder_10 100306 If yu d nt have a dwg drawing f the flr If yu have a dwg drawing f the flr Yes D yu have AutCad Expertise? N Prepare prper layers in AutCad 1 Imprt dwg t Builder Generate structural mdel 2 Simplify/preprcess the imprted drawing Validate the mdel under selfweight Enter/edit material Enter/edit design criteria Enter lads Lad cmbinatins Validate the slutin Analyze structure N Enter/imprt PT tendns Enter base reinfrcement Create design strips Create design sectins Design/cde check the structure Examine the design Exit t generate structural dcuments Yes Is design acceptable Mdify structure r ther parameters. Try again N 3 4 Rebar drawing PT drawing Structural calculatin reprt 5 Fabricatin drawing 1 1 (shp/installatin drawing) Refer t ntes and references 2
Technical Nte Mesh the structural mdel Obtain a slutin fr the selfweight f the flr system nly Validate the slutin btained by examining the deflected shape f the structure in 3D viewer and evaluating the value f the maximum deflectin reprted Make crrectins t the mdel, until satisfied Save data View/Edit Material Prperties 7 View/edit cncrete material prperties. Nte the cncrete weight specified fr use in selfweight calculatin View/edit steel material prperties View/edit Prestressing material prperties Save data View/Edit Design Criteria Select/verify the building cde t be used View/edit the items listed under analysis and design ptins Select the type f reinfrcement yu prefer fr punching shear design, stirrups r shear studs Select the size f reinfrcement bars t be selected by the prgram fr bending and neway shear View each f the ther tabs f the design criteria and edit the default values if necessary Save data Apply Lads If the lad cases yu plan t use are mre than dead, live, selfweight and prestressing d the fllwing 8 : G t Lad Case Library and enter the label f the ther lad cases that yu plan t use. Once the label is listed in the library, enables yu t enter the assciated lads. Enter the lads f each lad case. Make sure that each lad yu enter is assigned t the crrect lad case listed in the lad case library. Review/Edit Lad Cmbinatins G t lad cmbinatin dialg windw. Depending n the building cde yu have selected, the prgram will display a number f lad cmbinatins. Review/edit the lad cmbinatins displayed in the lad cmbinatin dialg windw fr relevance and accuracy. Fr each f the default lad cmbinatins and the nes yu are ging t add, make sure that the crrect Analysis/Design Optin is selected. In mst cases yu wuld select N Cde Check. If nt clear, click the Help buttn n the same dialg windw t be guided in yur selectin. It is nt necessary, but is advisable t create a lad case fr prestressing nly PT with n cde check fr evaluatin f the pst-tensining yu have entered. 7 If yu als intend t use the structural mdel fr exprt t PT, yu need t enter the material prperties fr bth Strip methd (EFM) and the Finite Element Methd (FEM) 8 Nte that a lad case is different frm lad cmbinatin. Using basic lad cases, yu can cmbine them in many different ways. The lad cases are the basic cnstituents f the lad cmbinatins. The prestressing lad case includes bth prestressing and hyperstatic cases. 3
Technical Nte Likewise, if yu have unusual lad cases, make sure that fr each f the lad cases yu define a lad cmbinatin. The bjective is t be able t view the results f the unusual lad case n its wn, in rder t evaluate its validity. Befre clsing the lad cmbinatin by pressing OK, make sure that yu have at least ne instance each f the fllwing required cde checks: Serviceability, Strength, Initial Cnditin, Enter/Edit Base Reinfrcement Base reinfrcement is the reinfrcement yu like t place in the structure, regardless f the utcme f the calculatins. But, at the same time, yu want presence f the reinfrcement yu have specified as base reinfrcement t be fully accunted fr in design. That is t say, yu want the prgram t reprt nly the reinfrcement needed in excess f what yu have specified. The base reinfrcement generally cnsists f a bttm and r tp mesh, pre-defined bars at the tp f clumns (number, size and length) 9, and pre-defined lngitudinal bars at the crners f beam cages. Enter mesh reinfrcement, if any Enter beam reinfrcement (crner bars), if yu require specific number and size Enter single bars in size, length and number at lcatins f yur chice. Verify each f the reinfrcement types n the cmputer screen Save Enter Pst-Tensining Tendns Enter the pst-tensining tendns fr the entire structure. 10 If nt clear, use the Guidelines fr Tendn Layut. 11 View the tendns in 3D viewer with a magnificatin factr f 6 r mre fr the Z- directin. Hide the walls and clumns t btain a gd view f the slab and its interir. Make sure that the tendn prfiles are acceptable. The mst cmmn mdificatins yu need t d are: Tendns in shrt spans shuld nt have a full drape. This may result in excessive uplift. In shrt cantilevers, tendns ver the exterir supprt shuld be lwered, in rder t avid excessive uplift. Save Analyze Structure If, apart frm pst-tensining, yu have nt applied a hrizntal frce t the structure, simply click n Analyze the Structure. Hwever, if yu have applied a hrizntal frce t the structure click n the Analysis Optins and disable the Autmatic Stabilizatin f the prgram. Apply prper bundary cnditins t keep the structure in psitin. 12 Save 9 In many instances, yu may wish t place a given number f bars f pre-defined size and length ver the supprt in a given directin. The prgram allws yu t define these and will reprt whatever is needed in additin t yur pre-defined bar layut. 10 Use Guidelines fr Tendn Layut if yu are nt clear n the tendn layut. 11 A pwerful alternative is t exprt the infrmatin t ADAPT-PT, determine the ptimum pst-tensining and imprt the ptimum values and layut back int FLOOR-Pr. Refer t FLOOR-Pr prgram manual fr mre infrmatin n this feature. 12 The autmatic stabilizatin add adequate supprts t what yu have specified, in rder t make sure that the structure is stable, withut changing the utcme f lad distributin f yur prject. But, if yu disable the autmatic stabilizatin, yu must make sure that yu specify adequate supprts fr the structure t resist the lads withut mving. 4
Technical Nte View/Validate Analysis Results G t 3D viewer and view the deflected shape f the structure fr the principal lad cases. These are service, pst-tensining and ther lad cases that yu have defined. If the deflected shapes and their magnitudes appear acceptable, yu may prceed t the design stage. Otherwise, adjust r crrect the suspect data r parameters. Create Design Strips in X-directin Use the supprt line wizard t create supprt lines alng ne f the principal axes f the structure. If the supprts d nt line up, the supprt line will nt be straight. This shuld nt be a cncern, since the prgram can autmatically adjust the directin f the calculated reinfrcement t that f yur chice independent frm the rientatin f assciated supprt lines. Create Design Strips fr the supprt lines created abve. Use the FEM ptin fr design strip creatin. Use the clr rendering f the design strips t make sure that the strips created cver the entire flr area. Each part f the flr area must have been assigned t a design strip. Crrect the errrs if any. If based n yur judgment, the gemetry f the strips created by the prgram is nt a gd arrangement, use splitters t mdify the prgram s chice. Re-create the design strips, until the selectin is acceptable t yu. Save Create Design Strips in Y-directin Fllw the abve prcedure t create design strips rthgnal t the first directin. Select the X and Y strips t be as clse t rthgnal cnditin as practical. Save Create Design Sectins Click n the Create Design Sectins Autmatically t generate design sectins fr each f the design strips. Activate the Display Design Sectins tl frm the Supprt Line Results/Scale Tlbar t view the design sectins generated fr each f the tw rthgnal directins. Verify the fllwing: If the number f sectins fr any given span is nt adequate, select the assciated supprt line and increase the number f design sectins. 13 There shuld be a design sectin at each face f a supprt (wall, clumn, beam) There shuld be a design sectin at the face f each drp cap/panel. Make sure that fr each directin the design sectins adequately cver the entire surface f the flr. Save Design the Design Sectins 13 The default f the prgram is 12 sectins in each span. This can be mdified by pening the prperty bx f a supprt line and changing the default value. 5
Technical Nte Activate the cde check f the structure and the calculatin f the necessary reinfrcement by selecting Design the Design Sectins. The prgram reprts the design sectins that d nt meet the minimum requirements f the cde in brken magenta lines. Otherwise, the design sectins will be shwn in green. Green display f a design sectin means that the cde requirements fr that sectin are met. View Details f the Design Outcme and Make Adjustments if Necessary T accept the design, select several f the critical design strips ne after the ther, and view the utcme f the design by displaying the fllwing: Reinfrcement reprted fr each cde check and the envelpe f reinfrcement The layut f reinfrcement (selectin f bar size, and length) Cmputed stresses and their cmparisn with the allwable values View the stress details f each f the design strips that have failed the cde check. Based n the lcatin f the design sectin, use yur judgment t determine which f the entry values have t be adjusted. In mst cases, the amunt and prfile f pst-tensining is the chice. Make the necessary mdificatin and repeat the analysis/design. Perfrm Punching Shear Check 14 Select the Punching Shear Check tl t perfrm cde check fr punching shear. View the values f the punching shear reprted by the prgram n the screen. If necessary and permissible, the prgram reprts the necessary reinfrcement. The prgram als reprts, if a sectin des nt pass Cde. Save data CONCLUSION OF DESIGN Once yu reach this stage, yur design is cmpleted. The steps t fllw are t prepare the structural dcuments. These are: Generatin f rebar drawings Generatin f pst-tensining drawings Generatin f shp drawings Generatin f the package f structural calculatins The prcedure fr the generatin f the each f the abve is detailed in a different dcument. 14 Punching shear check can als be perfrmed after the cmpletin f the analysis and prir t the design. Hwever, the advantage f perfrming punching shear check after the design ptin is that at each lcatin the prgram uses the actual value f precmpressin. In the frmer ptin, the prgram uses the minimum value f the cde (125 psi), assuming that an acceptable design must meet this value. 6
Technical Nte APPENDIX This Appendix explains in greater details sme f the terms used in the Technical Nte FRAMING PLAN Framing Plan is a drawing that is part f the structural dcuments and defines the utline f the cncrete flr system with all the details necessary fr its frming and finish. It prvides a cmplete definitin f the gemetry f the cncrete frming the flr system. In cntains the fllwing infrmatin: Full definitin f cncrete gemetry Cncrete utline Openings Steps abve and belw slab Drp caps/panels Slab bands Beams Slab thickness and beam dimensins Cncrete strength Prpsed cnstructin jints Prpsed clsure (pur) strips Supprts Lcatin f all wall supprts 15 Lcatin f all clumn supprts 16 Type f cnnectin f slab t supprts (extent and type f releases) 15 Walls identificatin and dimensins are shwn n ther drawings 16 Clumn identificatin and dimensins are shwn n ther drawings 7